With the advent of television networking, and in particular broadcasting of a common core program from a network studio to several regions or regional transmitters, a need has arisen for the transmission from a single studio of different sequences of play items simultaneously. This need arises in the following way. The network transmits a core programme of entertainment to transmitters servicing each region of the network simultaneously. However, each region of the network is based around a major population centre and its hinterland. As a result, the viewers of each region constitute separate markets for some types of advertisements. Thus during commercial breaks, local advertisers wish to have their advertisement displayed within their own region, but not also displayed within any of the other regions in the network.
As a consequence of this need, it is necessary for different advertisements to be displayed in each of the different regions in the network. Since each advertisement is not of an identical duration, it is necessary for the advertisements to be carefully scheduled in order that the commercial break at each station be of identical duration so that all commercial breaks can commence and finish simultaneously.
Hitherto, this requirement for simultaneous, but different, commercial breaks has been met by the network studio having a single channel automatic transmission system (ATS) for each region which arranges for the sequential transmission of each of the advertisements which is to be displayed during the commercial break.
However, such automatic transmission systems are relatively expensive pieces of equipment (A$250,000-A$1,000,000) including as they do an elaborate cartridge storage and retrieval system, and at least two and typically four VCR's which play respective cassettes in the sequence of advertisements.
In order to reduce overall costs in the network, it would be desirable to have a multi-channel automatic transmission system which could simultaneously broadcast different sequences of advertisements for each of the regions in the network during a network wide commercial break. Thus the central network studio need possess fewer ATS's to service the number of regions.